Developing sectors within the in depth Care box – and in severe Care drugs quite often – require particular degrees of competence having a comparable universal denominator: an in-depth wisdom of human pathophysiology. even if this quantity provides lots of subject matters in consistent evolution, as witnessed via the gathering of chapters compiled by means of numerous researchers, this variation contains, specifically, fields within which decision-making on the patient’s bedside prevails over theoretical argumentation. In different phrases, the 1st and most well known message this variation desires to offer is for the reader to concentration his/her consciousness on evidence-based medicine.

With PEEP the inflection point disappeared and the entire V’–V curve became concave toward the volume axis, indicating absence of EFL. (From [16] with permission) 22 A. Koutsoukou, J. Milic-Emili during mechanical ventilation in different body postures [12]. Based on this method, it has been shown that EFL is a rather common finding in mechanically ventilated patients. In fact, it has been shown that most mechanically ventilated patients with acute respiratory failure of pulmonary origin present tidal EFL [13], and also that most patients with acute respiratory distress syndrome exhibit EFL associated with a concomitant PEEPi [14, 15].

Although airway pressures are usually monitored clinically, transpulmonary pressures are clearly more relevant. The critical feature appears to be the degree of regional lung distension, rather than the absolute pressure reached. In addition to the obvious manifestations of overdistension, there are also more subtle types of injury that can be induced by mechanical ventilation. Wedd and Tierney [18] produced dramatic evidence that overdistension associated with high peak airway pressures could lead to the development of pulmonary oedema and death within 1 h in rats.

Pleural pressures plotted against lung volumes generate the chest wall P–V curve, and the lung P–V curve is constructed by plotting transpulmonary pressures (difference between airway and oesophageal pressure) against lung volumes. The pressure–volume curve 33 Traditional concepts about the P–V curve The inspiratory limb of the P–V curve consists of three segments separated by two inflexion points. The lower inflexion point (LIP) separates the first segment with low compliance (starting compliance) from the intermediate linear segment with a larger compliance (inflation compliance).